Lecture 1 (DESCRIPTIVE STATISTICS) Flashcards Preview

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Flashcards in Lecture 1 (DESCRIPTIVE STATISTICS) Deck (16)
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1
Q

UNGROUPED DATA

A

Have not been summarised in any way

RAW DATA

2
Q

GROUPED DATA

A

Have been organised into a frequency distribution.

3
Q

FREQUENCY DISTRIBUTION

A
Summary of data presented in the form of class intervals and frequencies. 
Vary in shape and design.
Constructed according to the individual researcher's preferences.
4
Q

Steps in producing a frequency distribution.

A

1: Determine the range of frequency distribution.
2: Determine the number of classes - min 5, max 15
3: Determine the width of the class interval. Dividing range by the number of classes.
Round to a convenient number.

5
Q

Why should the number of classes be between 5 and 15?

A

Fewer than 5 classes causes excessive summarisation.

More than 15 leaves too much detail.

6
Q

Class midpoint.

A
The midpoint of each class interval. 
= beginning class endpoint + ending class end point /2
7
Q

RELATIVE FREQUENCY

A
The relative frequency is the proportion of the total frequency that is any given class interval in a frequency distribution. 
= individual class frequency / total frequency
8
Q

CUMULATIVE FREQUENCY

A

The cumulative frequency is a running total of frequencies through the classes of a frequency distribution.

9
Q

HISTOGRAM

A
Vertical bar chart of frequencies.  
It is a type of vertical bar chart where the area of each bar is equal o the frequency of the corresponding interval. 
Put data into class intervals.
10
Q

FREQUENCY POLYGON

A
Line graph of frequencies.
Constructed by plotting a dot for the frequencies at the class midpoints and connecting the dots.
11
Q

OGIVE

A
Line graph of cumulative frequencies.
Plotted by graphing a dot at each class endpoint for the cumulative frequency value and connecting the dots,
12
Q

PIE CHART

A

Proportional representation for categories of a whole.

13
Q

STEM AND LEAF PLOT

A

Graphical method displaying data by separating each number into two groups - a stem and a leaf

14
Q

PARETO CHART

A

Type of chart which contains both bars and a line graph.
Bars display the data in descending order, and the line graph shows the cumulative totals of each category, left to right. The purpose is to highlight the most important among a (typically large set of factors).

15
Q

SCATTER PLOT

A

Type of display using Cartesian coordinates to display value for two variables for a set of data. The data is displayed as a collection of points, each having the value of on variable determining the position on the horizontal axis and the value of the other variable determining the position on the vertical axis.

16
Q

How to construct a pie chart?

A

Proportion each value is of total value multiplied by 360.